Improved patient outcomes frequently do not follow from improved health care processes for chronic diseases and health behaviors because success depends on events outside the control of the health care system: patients'ability to alter unhealthy behaviors and manage their diseases. Although concepts such as health literacy and self-management have been important advances, outcomes remain far from optimal. To address this problem, we seek to develop the concept of "capability", defined as people's substantive freedom to achieve a desired lifestyle;that is, what real opportunities they have, given their resources. Stated differently, is the gap between what people know they should do and what they are actually able to do. The plan is for a series of studies to understand the role of capability in clinical success and how to successfully manage patients whose capability is limited. The first study, described in this application, is for initial development of a clinical tool to measure patient capability. Subsequent studies will test its predictive power for important behavioral and clinical outcomes in patients with obesity and type II diabetes mellitus. Ultimately the goal is to measure and effectively manage, through better community partnerships, patient capability in managing health behaviors. In this study, using a community participatory research model, we collaborate with the Edgewood Family Network, a grassroots non-profit agency serving a disadvantaged Latino community in San Antonio, to develop an instrument that can be used by primary care practices to assess the capability of patients with obesity and type 2 diabetes mellitus to improve key health behaviors. EFN promotoras trained in qualitative methods and a qualitative investigator will recruit 14 community focus groups, 7 with obesity, and 7 with type 2 diabetes mellitus. Transcripts will then be coded and analyzed by the team of investigators, with interpretive consultation from the promotoras. From the focus group data, a clinical instrument will be developed and its psychometric properties evaluated in a clinical population. The next anticipated study is to validate the utility of the instrument for predicting clinical outcomes such as improvement in diet and physical activity in primary care patients. The research program is significant because it will develop tools and strategies to address the barriers that account for many health disparities in achieving healthy lifestyles and reducing chronic illness.